Completion assemblies for downhole operations are typically conveyed to a desired location within the wellbore and anchored or positioned within the wellbore by a service tool. Upon placement of the completion assembly, numerous well operations, such as perforation, fracing, gravel packing, etc., can be performed using a variety of completion tools, such as sand screens, bridge plugs, packers, pumps, just to name a few. Successful completion of these operations typically requires numerous movements of the service tool to actuate or operate the respective completion tools. For successful operations, an operator must have knowledge of the downhole service tool as well as an ability to visualize the operation, location, and status of the service tool within the well.
In a typical operation, the operator runs a work string, a service tool, and a lower completion into the well bore until a desired location is reached. The operator then marks the work string at the surface to indicate the respective location of the tool within the lower completion. The work string and the service tool are decoupled from the lower completion, and the work string and service tool are longitudinally moved within the lower completion. As the service tool is moved within the lower completion, the marks on the service tool are assumed to indicate specific positions of the service tool within the lower completion.
This procedure, however, relies on substantial knowledge and experience of the operator and is prone to error. Such error is most typically caused by the expansion and contraction of the work string as it is lowered into and retrieved from the wellbore. Such length differentials are most likely caused by temperature and/or pressure fluctuations within the wellbore that cause the work string to expand or contract. Moreover, in highly deviated wellbores with difficult trajectories, much of the string movement is lost between the surface and the downhole location due to string buckling, compression, and the like. In such systems where gravel packs are performed, the service tool can be prone to sticking with respect to the downhole completion assembly.
There is a need, therefore, for a downhole tool capable of performing multiple downhole operations without requiring longitudinal movement relative to the wellbore.